//
// detail/resolver_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_DETAIL_RESOLVER_SERVICE_HPP
#define ASIO_DETAIL_RESOLVER_SERVICE_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"

#if !defined(ASIO_WINDOWS_RUNTIME)

#include "asio/ip/basic_resolver_query.hpp"
#include "asio/ip/basic_resolver_results.hpp"
#include "asio/detail/concurrency_hint.hpp"
#include "asio/detail/memory.hpp"
#include "asio/detail/resolve_endpoint_op.hpp"
#include "asio/detail/resolve_query_op.hpp"
#include "asio/detail/resolver_service_base.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
    namespace detail {

        template<typename Protocol>
        class resolver_service :
                public execution_context_service_base<resolver_service<Protocol> >,
                public resolver_service_base {
        public:
            // The implementation type of the resolver. A cancellation token is used to
            // indicate to the background thread that the operation has been cancelled.
            typedef socket_ops::shared_cancel_token_type implementation_type;

            // The endpoint type.
            typedef typename Protocol::endpoint endpoint_type;

            // The query type.
            typedef asio::ip::basic_resolver_query<Protocol> query_type;

            // The results type.
            typedef asio::ip::basic_resolver_results<Protocol> results_type;

            // Constructor.
            resolver_service(execution_context &context)
                    : execution_context_service_base<resolver_service<Protocol> >(context),
                      resolver_service_base(context) {
            }

            // Destroy all user-defined handler objects owned by the service.
            void shutdown() {
                this->base_shutdown();
            }

            // Perform any fork-related housekeeping.
            void notify_fork(execution_context::fork_event fork_ev) {
                this->base_notify_fork(fork_ev);
            }

            // Resolve a query to a list of entries.
            results_type resolve(implementation_type &, const query_type &qry,
                                 asio::error_code &ec) {
                asio::detail::addrinfo_type *address_info = 0;

                socket_ops::getaddrinfo(qry.host_name().c_str(),
                                        qry.service_name().c_str(), qry.hints(), &address_info, ec);
                auto_addrinfo auto_address_info(address_info);

                return ec ? results_type() : results_type::create(
                        address_info, qry.host_name(), qry.service_name());
            }

            // Asynchronously resolve a query to a list of entries.
            template<typename Handler, typename IoExecutor>
            void async_resolve(implementation_type &impl, const query_type &qry,
                               Handler &handler, const IoExecutor &io_ex) {
                // Allocate and construct an operation to wrap the handler.
                typedef resolve_query_op <Protocol, Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(impl, qry, scheduler_, handler, io_ex);

                ASIO_HANDLER_CREATION((scheduler_.context(),
                        *p.p, "resolver", &impl, 0, "async_resolve"));

                start_resolve_op(p.p);
                p.v = p.p = 0;
            }

            // Resolve an endpoint to a list of entries.
            results_type resolve(implementation_type &,
                                 const endpoint_type &endpoint, asio::error_code &ec) {
                char host_name[NI_MAXHOST];
                char service_name[NI_MAXSERV];
                socket_ops::sync_getnameinfo(endpoint.data(), endpoint.size(),
                                             host_name, NI_MAXHOST, service_name, NI_MAXSERV,
                                             endpoint.protocol().type(), ec);

                return ec ? results_type() : results_type::create(
                        endpoint, host_name, service_name);
            }

            // Asynchronously resolve an endpoint to a list of entries.
            template<typename Handler, typename IoExecutor>
            void async_resolve(implementation_type &impl, const endpoint_type &endpoint,
                               Handler &handler, const IoExecutor &io_ex) {
                // Allocate and construct an operation to wrap the handler.
                typedef resolve_endpoint_op <Protocol, Handler, IoExecutor> op;
                typename op::ptr p = {asio::detail::addressof(handler),
                                      op::ptr::allocate(handler), 0};
                p.p = new(p.v) op(impl, endpoint, scheduler_, handler, io_ex);

                ASIO_HANDLER_CREATION((scheduler_.context(),
                        *p.p, "resolver", &impl, 0, "async_resolve"));

                start_resolve_op(p.p);
                p.v = p.p = 0;
            }
        };

    } // namespace detail
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // !defined(ASIO_WINDOWS_RUNTIME)

#endif // ASIO_DETAIL_RESOLVER_SERVICE_HPP
